Anthony Tommasini weighs in on Lorin Maazel’s new opera “1984”: “Unfortunately, though there are some compelling elements to “1984” and the creators received a fairly rousing ovation by the expectant audience, the opera is hampered by Mr. Maazel’s undistinguished score. The music is never less than thoroughly professional. But Mr. Maazel lacks a personal voice as a composer. What constitutes a compositional voice is hard to define. But you know it when you hear it.”